Document Detail

Reduction of ST elevation in repeated coronary occlusion model depends on both altered metabolic response and conduction property.
MedLine Citation:
PMID:  14659856     Owner:  NLM     Status:  MEDLINE    
The aim of this study was to elucidate the mechanisms of altered electrical response to ischemia in repeated coronary occlusion model. To test its dependence on metabolic response, extracellular K+ concentration (eKC), myocardial pH and PCO2 were simultaneously measured with epicardial ECG during three consecutive 4 min of left anterior descending coronary artery (LAD) occlusion separated by 15 min of reperfusion in canine hearts. ECG changes induced by infusion of high K+-buffer (10 mM) into the coronary arterial bed via carotid artery-LAD bypass (referred to as high K+-challenges: HKC) were also tested prior to (the first HKC), and during each reperfusion period (the second to the fourth HKC). ST elevation was significantly reduced in subsequent occlusions (3.14 +/- 0.48 and 2.98 +/- 0.47 mV in the second and third occlusion, both P<0.05, compared to 4.91 +/- 0.78 mV in the first). This was accompanied by significant attenuation of the changes in eKC, tissue pH and PCO2. ST elevation induced by HKC also significantly reduced after repeated occlusion (4.09 +/- 0.79 mV in the fourth HKC vs. 5.64 +/- 0.68 mV in the first, P<0.05) in spite of the identical changes in eKC during HKC. This progressive decrease in ST changes by HKC was rather consistent with augmented conduction delay (86.4 +/- 7.1% increase in activation time in the fourth vs. 54.3 +/- 3.4% in the first, P<0.01). These findings indicate that repeated ischemia induces altered electrical response to subsequent ischemia based on both attenuated metabolic response and altered conduction property.
Takashi Saito; Hiroto Miura; Yutaka Kimura; Hiroyuki Watanabe; Akira Nakagomi; Yoshikazu Tamura; Hitoshi Hasegawa; Satoshi Kibira; Mamoru Miura
Related Documents :
8066986 - Effects of halothane, enflurane, and isoflurane on supraventricular and ventricular rat...
22153866 - The beneficial effects of deferred delivery on the efficiency of hydrogel therapy post ...
6858886 - Sympathetic denervation limited to a region of acutely ischemic canine myocardium incre...
22297726 - Coffee component 3-caffeoylquinic acid increases antioxidant capacity but not polypheno...
18475136 - Characterization of the electroanatomic substrate in a case of noncompaction left ventr...
23977036 - Decreased autophagy contributes to myocardial dysfunction in rats subjected to nonletha...
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  International journal of cardiology     Volume:  92     ISSN:  0167-5273     ISO Abbreviation:  Int. J. Cardiol.     Publication Date:  2003 Dec 
Date Detail:
Created Date:  2003-12-08     Completed Date:  2004-04-29     Revised Date:  2007-11-15    
Medline Journal Info:
Nlm Unique ID:  8200291     Medline TA:  Int J Cardiol     Country:  Ireland    
Other Details:
Languages:  eng     Pagination:  219-27     Citation Subset:  IM    
The Second Department of Internal Medicine, Akita University, 1-1-1 Hondo, Akita 010-8543,
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Carbon Dioxide / metabolism
Coronary Disease
Energy Metabolism
Heart Conduction System / physiology
Hemodynamics / physiology
Hydrogen-Ion Concentration
Ischemic Preconditioning, Myocardial
Myocardial Reperfusion Injury / physiopathology
Myocardium / metabolism
Potassium / metabolism
Reg. No./Substance:
124-38-9/Carbon Dioxide; 7440-09-7/Potassium

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  Evidence of ischemic preconditioning in patients experiencing first non-ST-segment elevation myocard...
Next Document:  Fractional shortening-velocity ratio for assessment of aortic stenosis severity in patients with sys...